Pump for refrigerating apparatus



Oct. 25, 1932. 0 m; SUMMERS PUMP FOR REFRIGERATING APPARATUS Filed March so, 1929 Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE OTTO I. smms, Ol' DAYTON, OHIO; ASSIGNOB TO FBIGIDAIBE CORPORATION, OI DAYTON, OHIO, -.L CORPORATION OF DELAWARE rm roa' mmemrmc APPARATUS Application ma 11:01:80, 1929. Serial in. 351,345.

This invention relates to refrigerating apparatus and especially to the provision-of valves in certain portions of the refrigerating system. I

An object of the invention is to provide a check valve for operation when the com-- pressor stops. Y Another object of the invention is the provision of a check valve in order that the compressor valve ma be designed from the standpoint of an e cient and quiet operation.

Another. object of-the invention is the provision of a plurality of valves whereby the refrigerant will not become excessively heated in passing from the low pressure tothe high pressure side of the system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the invention is clearly shown.

In the drawing:

Fig. 1 is a vertical-cross section thru the top of a compressor and check valves attached thereto.

Fig. 2 is a top view of the valve plate and its valves employed in the compressor disclosed in Fig. 1.

Fig. 3 is a more or less diagrammatic arrangement of refrigerating apparatus to which the invention may be applied.

One of the problems confronting inventors designing refrigerating apparatus is the design of the valves separating the low pressure and high pressure portlons in the system. These valves heretofore had to be designed not onlyfrom an efiicient pumping standpoint but also so designed as to withstand the back pressure of the refrigerant when the compressor stops. It has heretofore been the custom to use a relatively small valve in the valve plate with the result that the valve had to lift a relatively great distance to permit the required amount of refrigerant to pass therethrough. The consequence-of this rather high lift is a tendency to produce considerable heat in the valve plate. The back slap of the valve also has a tendenc to roduce noise which isvery undesirab e in ousehold appliances in constant or intermittent operation. Accordingly the invention contemplates the provision of an additional fluid pressure operated valve that will operate asa check valve when the thru the larger valve seats and this results.

in less heat than in the case of a high lift and strong back slap of the valves of the prior art. On' the other hand, the same amount of valve lift could be retained with the new arrangement and a much slower acting compressor designed with the result that the force of the back slap and the noise therefrom is reduced.

Fig. 3 discloses some of the usual refrigerator elements used in certain types of refrigerating apparatus. It is not intended to limit the application of the invention to particular forms disclosed as such forms are used merely by way of illustration. A compressor 1O forwards the compressed gas to the condenser 11 where the refrigerant is changed to a liquid by any convenient cooling means such as a fan and then descends to receiver 12. From the receiver 12 the refrigerant is sent to a cooling unit 13 preferably of a-flooded float control type illustrated in the patent to R. G. Osborn, 1,556,708 i$ued October 13, 1925. Upon evaporation the refrigerant now in a gas form returns by means of the conduit 14 to the compressor 10. A conduit 15 preferably leads from the conduit 14 to a bellows 16 controlling a snap switch 17 which actuates a set of contacts interposed in the electrical connections 18 of the motor 19. The motor 19 is connected to and runs the compressor by means of a belt 20 and compressor pulley 21. Suitable cooling means for the compressor and. motor, such as fans, may be installed if desired. In

I this system the high pressure side or portion extends from the top of the valve plate of the com ressor to the cooling unit where the refrigerant is evaporated. The low pressure side extends from the cooling ;unit to the underside of the valve plate. This invention is especially concerned with the elements and conditions about the low pressure and-high pressure boundary at the valve plate.

' In 1 is illustrated the elements dividing the low pressure side from the hlgh pressure side of the system within the compressor. The refrigerant preferably sulphur dioxide, altho methyl chloride, ethylchloride, ammonia or their equivalents may be used, is re turned to the compressor 10 in a gaseous state. Within the compressor are one ,or more pistons preferably two reciprocating pistons 24 mounted upon a crank shaft or upon eccentries on a straight shaft as desired. The gas preferably enters the upper portion of the cylinder body 22 by means of the gas port 25 altho there-may instead or-in addition be valves or some such entry in the pistons 24. Fins 23 uponxthe cylinder body aid in the dissipation of heat. -Upon the cylinder body 22 is the valve plate 26 with the comcompressor.

' pressor head 27 mounted thereon by means of the screws 28. Suitable gaskets 29 are inserted betweenzh'e head plate and body of the hru the valve plate are a. equally spaced on the circumference of a circle whose center coincides with the axis of the piston. At the upper end of these holes is preferably an annular valve seat 44. A valve, preferably .of spring steel covers those holes and is fastened to the valve plate by means of the screws 33. The valve preferably consists of a flat annular portion 31 supported by the flexible and preferably integral arms 32.

Upon the up-stroke of one of these pistons the gas is compressed in the passage ways 30 and when so compressed raises the valve and oassesthru to the head 27 in a compressed or high pressure state. Upon the down stroke of the piston the valve closes and compressed gas is passed thru the valve above the other piston if two or more pistons are used. Accordingly the valve plate and its valves mark the boundary between the low pressure and high pressure side of the system and gaseous refrigerant passes thru to the head' as long as the pistons are working.

The bellows 16 responds to the temperature pressure characteristics of the evaporator 13 and starts and stops the motor automatically. When the motor 19 is stopped the high pressure in the head 27 and its connections thereto will immediately react against'the valves 31. The valves 31 however have to be very thin for eflicient operation and with the large area as disclosed this back pressure might result in injurying the valves. Ac-

cordingly instead of using the smaller sized means for preventing t nausea valves of the prior art a plicant has designed hls back pressure effecting the valves. A referred form of this means is disclosed in Fig. 1 altho it is not intended to limit the invention to the specific type of apparatus'disclosed. A connection 34 preferably L-shapcd extends from the compressor head 27 to a check valve which in its preferred form includes two casing members 35 and 36. In the lower part of the casing 35 is a reservoir for a fluid preferably a liquid such as oil. The casing 35 preferably has a valve seat 41 therein for a valve 40 of a some what conoidal shape. A stem 39 is preferably connected to the valve and extends downward to a piston 38 preferably of conoidal shape in the liquid 37. Thus the piston 38 forms a slow acting'valve in the casing 35 by itsmoving against the resistance offered by the body of liquid 37. The specific structure is commonly referred to as a dash pot valve. Upon the upper part of the casing 35 is preferably an extension-42 having ports or openings 43 therein. With this arrangement when the pistons 24 and the valves 31 are operating the high pressure refrigerant flows thru the head 27 tothe connection 34, raises the check valve to the position in dotted lines and the refrigerant flows about the valve 40 on the inside and outside of the extension 42 and thence onward to the condenser 11 where it is cooled to'a liquid state. Thus, upon the down or intake stroke of the piston 24, the valve 31 will close on its seat and open upon the up or compreming stroke. As long as'the compressor is operating the fluid pres sure operated check valve 40 will remain open, Due to the damping effect of the oil the check-valve will not rattle up and down with any slight variation in the pressure of the refrigerant as it passes by the head of the check valve. When the piston 24 stops operating the refrigerant above the head of the check valvevwill force the head 40 down in its valve seat 41 and thus make the check valve operate to cut 01! the pressure of the high side of the system from affecting the valves 31. Thus the fluid pressure operated check valve 40 will seat only when the compressorv taken care of by the seating of the check valve 40 when the compressor is idle. Thus a much larger valve 31 and valve seat 44 can be used 7 than would otherwise be possible. By way of example the valve seat in a valve plate in a standard compressor with 1/ horse-power normally has a circumference of 1.27 inches without a check valve. The use of a check of 4.71 inches.

valve according to applicants invention allows the valve seat 44 to have a circumference Due to such an increase in size of the valve seat the compressed refrigerant would not have to pass so rapidly thru the valve and valve seat due to this increased area and accordingly less heat will be produced in the compressor valve plate and other elements connected thereto. Due to the fact that the piston 38 is positioned in a liqu d at all times, the check valve 40 will be quiet in operation especially as its preferred. con'oidal form directs the refrigerant gas equally about .its circumference.

While'the form of embodiment of the m r.

vention as herein disclosed constitutes preferred form, it is to be understood that other forms might be adopted, all coming withinthe scope of the claims which follow. What is claimed is as follows: v -1. A part of a refrigerating system, having a low pressure portion and a .high pressure portion, a pump for circulating refrigerant from said low pressu'reportion to said high pressure portion, a valve in said high pressure ortion normally closed when the pump is' .1dle, and a dash-pot for preventing closing of said valve while the pump is in operation.

2. A part of a refrigerating system, having a low pressure portion and a high pressure portion, a pump for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said high pressure portion normally closed when the pump is idle, means for preventing closing of said valve while the pump is in operation, and a valve between the low pressure portion and the high pressure portion for maintaining a differential in pressure in said portions while the refrigerant is circulated from the low to the high pressure portion.

3. A part of a refrigerating system having a low pressure portion and ahigh pressure portion, a pump for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said high pressure portion normally closed when the pump is idle, and means providing a time lag between the opening and closing of said valve for preventing closing of said valve while the pump is in operation, and a valve between the low pressure portion and the high pressure portion for maintaining a differential in pressure in said portions while the refrigerant is circulated from the low to the high pressure portion.

4. A part of a refrigerating system having a low pressure portion and a high pressure portion, a pump for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said high pressure portion normally closed when the pump is idle, a dash-pot for preventing closing of said valve while the pump is in operation, and a valve between the low pressure portion dug-ing and the high pressure portion for maintaininga differential in pressure in said ortions while the refrigerant is circulated rom the low to the high pressure portion.

5. A part of a refrigerating system having a low pressure portion and a high pressure portion, a pump having a reciprocating pistion for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said high pressure portion normally closed when the pump is idle, and means providing a time lag between the open- .ing and closing of said valve for preventing closing of said valve during the suction stroke of said piston.

, 7. A part of a refrigerating system having a low pressure portion and a high pressure portion, a pump having a reciprocating piston for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said highpressure portion normally closed when the pump is idle, and a dash-pot for preventing closing of said valve during thesuction stroke of said piston.

8. A part of a refrigerating system having alow pressure portion and a high pressure portion, a pump having a reciprocating piston for circulating refrigerant fromsaid low pressure portion tosaid high pressure portion, a'valve in said high pressure portion normally closed when the pump is idle, means for preventing closing of said valve during the suction stroke of said piston, and a valve between the low pressure portion and the high pressure portion for maintaining a differential in pressure in said portions while the refrigerant is circulated from the low to the high pressure portion.

9. A part of a refrigerating system havinga low pressure portion and a. high pressure-portion, a pump having a. reciprocating piston for circulating refrigerant from said low pressure portion to said high pressure portion, a valve in said high pressure por- .tion normally closed when the pump is idle,

means providing a time lag between the openpart of a refrigerating system having closing of said. valve during the suction stroke of said piston.

10. A part of a refrigerating system having a low pressure portion and a high pressure portion, a pump having a reciprocating piston for circulating refrigerant from said low pressure portion to-said high pressure portion, avalve in said high pressure portion normally closed when the pump is idle,

a dash-pot for preventing closin of said valve during the suction stroke 0 said piston, and avalve betweenthe low pressure portion and the high pressure portion for maintaining a differential in pressure in said portions w ile'the refrigerant is circulated from the low to the high pressure portion.

11. A part of a refrigerating system, having a low pressure portion an a high pressure portion, a" pump for circulating refrigerant from said low pressure portion to said high pressure portion, said pump having a relatively lar e discharge valve, a second valve in said high pressure portion beyond said discharge valve, said second valve bein normally closed whenthe pump is-idle, an means for maintaining said second valve continuously open while the pump is in operation.

In testimony whereof I hereto afiix my signature.

oT'ro Mr SUMMERS. 

